【摘要】：研究背景及目的：腹主動(dòng)脈瘤(AAA)是老齡化社會(huì)的常見病,發(fā)病隱匿,一旦破裂,死亡率達(dá)60～80%。炎癥、細(xì)胞外基質(zhì)降解、平滑肌細(xì)胞(SMC)凋亡及表型轉(zhuǎn)化、和氧化應(yīng)激等均是AAA發(fā)生的關(guān)鍵環(huán)節(jié)。巨噬細(xì)胞浸潤是腹主動(dòng)脈瘤(AAA)進(jìn)展的關(guān)鍵環(huán)節(jié),趨化因子受體CXCR2及配體對(duì)巨噬細(xì)胞在組織的浸潤起重要調(diào)節(jié)作用。但在AAA進(jìn)展過程中,CXCR2如何調(diào)節(jié)巨噬細(xì)胞浸潤,進(jìn)而降解細(xì)胞外基質(zhì)、引起氧化應(yīng)激,機(jī)制尚不清楚。因此,本實(shí)驗(yàn)采用CXCR2特異性抑制劑SB265610抑制CXCR2表達(dá),明確CXCR2對(duì)小鼠AAA形成的調(diào)節(jié)作用,闡明CXCR2促進(jìn)AAA進(jìn)展的具體分子機(jī)制。其次本實(shí)驗(yàn)收集AAA病人和正常人血漿,檢測(cè)血管生成素相關(guān)生長因子并探討其與腹主動(dòng)脈瘤直徑之間的關(guān)系。實(shí)驗(yàn)方法：(1)通過對(duì)雄性缺陷小鼠(ApoE-/-)皮下埋植血管緊張素Ⅱ (Ang Ⅱ)緩釋泵(1,000 ng/min/kg)的方法,復(fù)制動(dòng)物AAA模型； (2)通過腹腔注射SB265610 (2mg/kg·d)抑制CXCR2,因此小鼠分成四組：Control, SB265610, Ang Ⅱ, AngⅡ+SB265610。通過測(cè)量血管超聲、鼠尾監(jiān)測(cè)血壓及大體解剖觀察各組小鼠體內(nèi)動(dòng)脈大體形態(tài)及血壓變化；通過HE染色、Elastin染色和免疫組織化學(xué)染色法觀察各組小鼠組織結(jié)構(gòu)的變化和炎癥細(xì)胞浸潤；通過細(xì)胞流式技術(shù)分析各組小鼠組織和血中炎癥細(xì)胞的表達(dá)；通過PCR分析各組小鼠動(dòng)脈壁內(nèi)炎癥因子表達(dá)水平；通過DHE染色確定主動(dòng)脈壁內(nèi)氧化應(yīng)激的情況,通過免疫組織染色、Western Blot和明膠酶譜方法分析各組小鼠動(dòng)脈壁內(nèi)基質(zhì)金屬蛋白酶的表達(dá)及活性變化； (3)收集AAA病人及對(duì)照組血漿,通過ELISA方法檢測(cè)不同組血漿中AGF表達(dá)水平,并分析不同直徑腹主動(dòng)脈瘤血漿AGF之間的差異。結(jié)果：1.Ang Ⅱ刺激誘導(dǎo)ApoE-/-小鼠建立成功誘導(dǎo)建立AAA動(dòng)物模型；2.SB265610抑制CXCR2后顯著抑制Ang Ⅱ誘導(dǎo)的ApoE-/-小鼠AAA形成(發(fā)生率及直徑)；3. CXCR2被抑制后抑制Ang Ⅱ誘導(dǎo)的①動(dòng)脈壁內(nèi)巨噬細(xì)胞浸潤；②基質(zhì)金屬蛋白酶的表達(dá)及活性；③氧化應(yīng)激；4.腹主動(dòng)脈瘤患者的血漿AGF水平升高,且直徑較大的腹主動(dòng)脈瘤升高程度更明顯。結(jié)論：我們證明了CXCR2的激活可以促進(jìn)腹主動(dòng)脈瘤形成。其作用機(jī)制可能與血管緊張素Ⅱ誘導(dǎo)的巨噬細(xì)胞浸潤,MMP表達(dá)和活性增加,氧化應(yīng)激激活相關(guān)。CXCR2抑制劑SB265610可以抑制這些改變。而且,我們發(fā)現(xiàn)腹主動(dòng)脈瘤患者的血漿AGF水平升高,且升高的程度可以反映腹主動(dòng)脈瘤的大小。這些發(fā)現(xiàn)闡明了CXCR2參與AAA發(fā)生的病理生理學(xué)機(jī)制,為AAA治療提供了一個(gè)新的治療靶點(diǎn)；同時(shí)本研究還發(fā)現(xiàn)AGF在腹主動(dòng)脈瘤患者血漿中的變化,有一定的診斷及隨訪價(jià)值。
[Abstract]:Background and objective: abdominal aortic aneurysm (AAA) is a common disease in aging society. Inflammation, degradation of extracellular matrix, apoptosis and phenotypic transformation of smooth muscle cells (SMC), and oxidative stress are the key links of AAA. Macrophage infiltration is the key to the progression of (AAA) in abdominal aortic aneurysms. Chemokine receptor CXCR2 and ligand play an important role in regulating macrophage infiltration in the tissues. However, during the progress of AAA, it is unclear how CXCR2 regulates macrophage infiltration and degrades extracellular matrix and causes oxidative stress. Therefore, SB265610, a specific inhibitor of CXCR2, was used to inhibit the expression of CXCR2, to clarify the regulatory effect of CXCR2 on the formation of AAA in mice, and to elucidate the specific molecular mechanism of CXCR2 promoting the progression of AAA. Secondly, plasma samples were collected from AAA patients and normal subjects to detect angiopoietin related growth factors and to explore the relationship between angiopoietin and the diameter of abdominal aortic aneurysms. Methods: (1) Animal AAA model was established by subcutaneous implantation of angiotensin 鈪，

本文編號(hào)：2420308